Brithura stigmosa, Liu, Qifei & Yang, Ding, 2010

Liu, Qifei & Yang, Ding, 2010, Four new species of the genus Brithura Edwards from China, with an updated key to world species (Diptera, Tipulidae), Zootaxa 2401, pp. 52-60 : 58-60

Brithura stigmosa sp. nov.

( Figs. 4 , 17–20 )

Diagnosis. Antennal flagellum yellow. Prescutum stripes disintegrated into lines of subrectangular brown spots. Wing yellowish gray with Sc1 absent, costal border opposite stigma smooth. Tergites of abdomen chestnut brown with outer lateral angles yellow; sternites yellowish brown. Outer gonostylus with four processes, lateral pair ones caudad, pointed at tip, middle pair ones cephalad.

Description. Male. Body length 21.0 mm, wing 20.0 mm.

Head. Yellowish brown. Rostrum reddish brown, with dark reddish brown nasus. Vertex brown, occiput yellowish brown. Vertical tubercle blackish, tip pointed. Orbit brownish yellow. Hairs on head brownish.

Antenna 4.5 mm long; scape light reddish brown; pedicel yellow; flagellum yellow. Probocis dark reddish brown; palpus reddish brown, last segment blackish, setae short, brownish.

Thorax. Ground color brown. Pronotum brownish with central blackish brown; prescutum brown with four yellowish brown longitudinal stripes, each stripe disintegrated into two lines of subrectangular brown spots, lateral margin of prescutum dark reddish brown; scutellum blackish brown, each lobe with similar color patterned stripe; scutum grayish brown with lateral lobe reddish brown; mediotergite grayish red-brown; pleura chiefly brown, katepisternum upper with a blackish spot, pleurotergal tubercle small, with silvery pubescence on dorsal surface. Hairs on thorax brown. Coxae and trochanters brownish yellow; femora dark brownish yellow, tips brown, preceded with a subequal yellow ring; tibiae dark brownish yellow; tarsi brown; tibial spurs 1–1–2. Hairs on coxae and trochanters yellow, on other segments of legs brown. Wing ( Fig. 4 ) with Sc1 absent. Wing yellowish gray with costal region opposite stigma smooth. Cells c and sc yellow. Stigma brown. A brownish spot at origin of Rs; area from stigma to cell dm along cord brownish, surrounded by yellowish suffusion; cell dm with brownish spot at outer half; brownish spot at both sides of middle A1 at midlength. Veins yellow. Halter with stem yellowish brown, knob more blackish but brownish yellow at tip.

Abdomen. Ground color chestnut brown. Tergite 1 brown, tergites 2–8 chestnut brown with outer lateral angles yellow. Venter yellowish brown with outer half more brownish. Hairs on abdomen brownish.

Hypopygium ( Figs. 17–20 ). Tergite 9 ( Fig. 18 ) with caudal margin shallowly U-shaped emarginate that is fringed with long yellow setae; sternite 9 ventrally with a reddish brown knob; outer lobe of outer gonostylus ( Fig. 19 ) with three processes, outer one caudad, point at tip, middle one cephalad, tip with two small processes, inner one cephalad, bent near tip, inner lobe of outer gonostylus bent backwards near pointed tip, another small process on caudal margin; inner gonostylus ( Fig. 20 ) with upper margin curved, outer surface caved. Setae on gonostylus light brown.

Female. Unknown.

Type material. Holotype male, Henan: Songxian, Baiyunshan (1200 m), 2008. VIII. 14, Xingyue Liu.

Distribution. China (Henan).

Remarks. This new species is different from any other species of the genus Brithura by the absence of Sc 1 in the males. It is similar to B. sancta Alexander, 1929 in the coloration of the legs and wing. It can be easily separated from B. sancta by the absence of Sc1, the pattern of the prescutum and structure of the hypopygium. In B. sancta, Sc 1 is preserved, the strips on the prescutum are continuous, the outer gonostylus is straight, and the spine of the outer gonostylus is very short ( Alexander 1929).

Etymology. The species name is based on the lines of the subrectangular brown spots forming prescutum stripes.

Figures

FIGURES 1 – 4. Wing (male). 1. Brithura shii sp. nov.; 2. Brithura aureola sp. nov.; 3. Brithura flaviflagellum sp. nov.; 4. Brithura stigmosa sp. nov.;

FIGURES 17 – 20. Brithura stigmosa sp. nov. Male. 17. Hypopygium, lateral view; 18. ninth tergite, dorsal view; 19. inner gonostylus, lateral view; 20. outer gonostylus, lateral view. Scale bar of 17, 18 = 0.5 mm, 19, 20 = 0.25 mm.